Efficacy and safety of varenicline for smoking cessation in patients with cardiovascular disease: a randomized trial

Abstract

Background: Smoking cessation is a key component of secondary cardiovascular disease prevention. Varenicline, a partial alpha4beta2 nicotinic acetylcholine receptor agonist, is effective for smoking cessation in healthy smokers, but its efficacy and safety in smokers with cardiovascular disease are unknown.

Methods and results: A multicenter, randomized, double-blind, placebo-controlled trial compared the efficacy and safety of varenicline with placebo for smoking cessation in 714 smokers with stable cardiovascular disease. Participants received varenicline (1 mg twice daily) or placebo, along with smoking-cessation counseling, for 12 weeks. Follow-up lasted 52 weeks. The primary end point was carbon monoxide-confirmed continuous abstinence rate for weeks 9 through 12 (last 4 weeks of treatment). The continuous abstinence rate was higher for varenicline than placebo during weeks 9 through 12 (47.0% versus 13.9%; odds ratio, 6.11; 95% confidence interval [CI], 4.18 to 8.93) and weeks 9 through 52 (19.2% versus 7.2%; odds ratio, 3.14; 95% CI, 1.93 to 5.11). The varenicline and placebo groups did not differ significantly in cardiovascular mortality (0.3% versus 0.6%; difference, -0.3%; 95% CI, -1.3 to 0.7), all-cause mortality (0.6% versus 1.4%; difference, -0.8%; 95% CI, -2.3 to 0.6), cardiovascular events (7.1% versus 5.7%; difference, 1.4%; 95% CI, -2.3 to 5.0), or serious adverse events (6.5% and 6.0%; difference, 0.5%; 95% CI, -3.1 to 4.1). As a result of adverse events, 9.6% of varenicline and 4.3% of placebo participants discontinued study drug.

Conclusions: Varenicline is effective for smoking cessation in smokers with cardiovascular disease. It was well tolerated and did not increase cardiovascular events or mortality; however, trial size and duration limit definitive conclusions about safety. Clinical Trial Registration Information- URL: http://www.clinicaltrials.gov/ct2/show/NCT00282984. Unique identifier: NCT00282984.

Figure 1

Participant disposition. Flow of participants through the study.

Figure 2

Tobacco CARs. Proportion of participants who reported abstinence from tobacco smoking, confirmed by exhaled CO ≤10 ppm, at all visits during the time period. *Primary study end point (weeks 9 to 12 are the last 4 weeks of study drug treatment).

Figure 3

Seven-day point prevalence tobacco abstinence rates. CO-validated abstinence from any tobacco product in the past 7 days. For varenicline (closed circles) vs placebo (open squares): *week 12: OR, 6.05; 95% CI, 4.23 to 8.65; P<0.0001; †week 24: OR, 2.98; 95% CI, 2.07 to 4.29; P<0.0001; ‡week 52: OR, 2.10; 95% CI, 1.45 to 3.05; P<0.0001.